24 GEORGE JOHN ROMANES i*w 



I should like to have your opinion about the 

 meaning of the following facts. 



In Sarsia gentle irritation of a tentacle or an eye- 

 speck causes the polypite to respond, but not the 

 bell (stronger irritation, of course, causes both to 

 respond) ; this seems to show that there are nervous 

 connections between the eye-specks and the polypite. 

 By introducing cuts between former and latter, these 

 connections may be destroyed — the tolerance of the 

 tissue to such sections being variable in different 

 cases, but never being anything remarkable. So far, 

 then, the matter seems favourable to the nerve-plexus 

 theory. 



In another disc-shaped species of naked-eyed 

 Medusae with a long polypite, which I have called 

 Tiaropsis indicans, from its habit of applying this 

 long polypite to any part of the bell which is being 

 injured, the localising function of the polypite is de- 

 stroyed as regards any area of bell-tissue between 

 which and the polypite a circumferential section has 

 been introduced. In other words, the connections 

 between the bell and the polypite, on which localis- 

 ing function of the latter depends, are exclusively 

 radial. But not so the connections between the bell 

 and the polypite, which render it possible for the 

 one to be aware that something is wrong somewhere 

 in the other. For if the whole animal be cut into 

 a spiral with the polypite at one end, irritation of 

 the other end of the spiral, or any part of its length, 

 causes the polypite to sway about from side to side 

 trying to find the offending body. And here it is 

 important to observe that wherever a portion of one 



